Day: May 13, 2025

What’s An LCR Databridge?

May 13, 2025 by 1 Comment

[Thomas Scherrer] has an odd piece of vintage test equipment in his most recent video. An AIM LCR Databridge 401. What’s a databridge? We assume it was a play on words of an LCR bridge with a digital output. Maybe. You can see a teardown in the video below.

Inside the box is a vintage 1983 Z80 CPU with all the extra pieces. The device autoranges, at least it seems as much. However, the unit locks up when you use the Bias button, but it isn’t clear if that’s a fault or if it is just waiting for something to happen.

The teardown starts at about six minutes in. Inside is a very large PCB. The board is soldermasked and looks good, but the traces are clearly set by a not-so-steady hand. In addition to AIM, Racal Dana sold this device as a model 9341. The service manual for that unit is floating around, although we weren’t able to download it due to a server issue. A search could probably turn up copies.

Continue reading “What’s An LCR Databridge?” →

A Web Based Controller For Your Garage Door

May 13, 2025 by 4 Comments

Garage doors! You could get out of your vehicle and open and close them yourself, but that kinda sucks. It’s much preferable to have them raise and lower courtesy some mechanical contrivance, and even better if that is controlled via the web. [Juan Schiavoni] shows us how to achieve the latter with their latest project.

The web-based controller is based around a Xiao ESP32 microcontroller board, chosen for its baked-in WiFi connectivity. It’s set up to host its own web interface which you can login to with a password via a browser. If you have the correct authorization, you can then hit a button to open or close the garage door.

To interface the ESP32 with the garage door itself, [Juan] went the easy route. To trigger opening or closing the door, the ESP32 merely flicks an IO pin to toggle a transistor, which is hooked up to the button of the original garage door opener. Meanwhile, the ESP32 is also hooked up with a magnetic switch which is activated by a magnet on the garage door itself. This serves as a crude indicator as to the current status of the door—whether currently open or closed. This is crucial to ensure the indicated door status shown in the web app remains synced with the status of the door in reality.

It’s a simple project, and reminds us that we needn’t always do things the hard way. [Juan] could have figured out how to hook the ESP32 up with some radio chips to emulate the original garage door opener, but why bother? hooking it up to the original remote was far easier and more reliable anyway. We’ve seen a good few garage door hacks over the years; if you’ve got your own unique take on this classic, don’t hesitate to notify the tipsline!

[Thanks to Stillman for the tip!]

Thermal Monocular Brings The Heat At 10X

May 13, 2025 by 3 Comments

[Project 326] is following up on his thermal microscope with a thermal telescope or, more precisely, a thermal monocular. In fact, many of the components and lenses in this project are the same as those in the microscope, so you could cannibalize that project for this one, if you wanted.

During the microscope project, [Project 326] noted that first-surface mirrors reflect IR as well as visible light. The plan was to make a Newtonian telescope for IR instead of light. While the resulting telescope worked with visible light, the diffraction limit prevented it from working for its intended purpose.

Continue reading “Thermal Monocular Brings The Heat At 10X” →

The frame of a delta 3D printer is shown. The toolhead of the 3D printer does not have a hotend installed, but instead has a frame with a circular hole in the middle.

A Toolchanging Delta 3D Printer

May 13, 2025 by 1 Comment

We’ve seen quite a few delta 3D printers, and a good number of toolchanging printers, but not many that combine both worlds. Fortunately, [Ben Wolpert]’s project fills that gap with a particularly elegant and precise delta toolchanger.

The hotend uses three steel spheres and triangular brackets to make a repeatable three-point contact with the toolhead frame, and three pairs of corresponding magnets hold it in place. The magnets aren’t in contact, and the three magnets on the toolhead are mounted in a rotating ring. A motorized pulley on the printer’s frame drives a cable which runs through a flexible guide and around the rotating ring.

The whole setup is very reminiscent of the Jubilee toolchanging system, except that in this case, the pulley rotates the ring of magnets rather than a mechanical lock. By rotating the ring of magnets about 60 degrees, the system can move the pairs of magnets far enough apart to remove the hotend without much force.

The rest of the toolchanging system is fairly straightforward: each tool’s parking area consists of two metal posts which slot through corresponding holes in the hotend’s frame, and the motherboard uses some RepRapFirmware macros to coordinate the tool changes. The only downside is that a cooling fan for the hotend still hadn’t been implemented, but a desk fan seemed to work well enough in [Ben]’s tests. The files for the necessary hardware and software customizations are all available on GitHub.

We’ve only seen a similar toolchanging system for a delta printer once before, but we have seen a great variety of toolchangers on the more common Cartesian systems. Don’t like the idea of changing extruders? We’ve also seen a multi-extruder printer that completely eliminates tool switching.

Continue reading “A Toolchanging Delta 3D Printer” →

Remembering Memory: EMS, And TSRs

May 13, 2025 by 27 Comments

You often hear that Bill Gates once proclaimed, “640 kB is enough for anyone,” but, apparently, that’s a myth — he never said it. On the other hand, early PCs did have that limit, and, at first, that limit was mostly theoretical.

After all, earlier computers often topped out at 64 kB or less, or — if you had some fancy bank switching — maybe 128 kB. It was hard to justify the cost, though. Before long, though, 640 kB became a limit, and the industry found workarounds. Mercifully, the need for these eventually evaporated, but for a number of years, they were a part of configuring and using a PC.

Why 640 kB?

The original IBM PC sported an Intel 8088 processor. This was essentially an 8086 16-bit processor with an 8-bit external data bus. This allowed for cheaper computers, but both chips had a strange memory addressing scheme and could access up to 1 MB of memory.

In fact, the 8088 instructions could only address 64 kB, very much like the old 8080 and Z80 computers. What made things different is that they included a number of 16-bit segment registers. This was almost like bank switching. The 1 MB space could be used 64 kB at a time on 16-byte boundaries.

So a full address was a 16-bit segment and a 16-bit offset. Segment 0x600D, offset 0xF00D would be written as 600D:F00D. Because each segment started 16-bytes after the previous one, 0000:0020, 0001:0010, and 0002:0000 were all the same memory location. Confused? Yeah, you aren’t the only one.

Continue reading “Remembering Memory: EMS, And TSRs” →

A man aims the LED flashlight into the night sky.

The World’s Longest Range LED Flashlight

May 13, 2025 by 24 Comments

[ApprehensiveHawk6178] reports that they have made the world’s longest range LED flashlight! While technically “handheld”, you’re gonna need both hands for this monster. According to the creator, it draws 1.2 kW (20 A @ 60 V) to deliver 100,000 lumens and approximately 20,000,000 candelas.

This spotlight is made from 48 white LEDs, wired in 16S3P configuration, and is powered by a similarly beefy 20S2P battery pack. That 1.2 kW power draw generates a lot of heat which is dissipated with an array of heat sinks and five cooling fans. Total cost was in the order of $2,000 USD.

It can be controlled via Bluetooth, and can run from its batteries for 30 minutes at full power. If you’d like to geek out over the specs click-through and read the discussion, a lot of technical detail is given and there are a bunch of photos showing the internals and assembly.

We’ve seen high-output LED lights with water cooling in the past, and wonder if that might be the next step for this particular build.

Thanks to [kms] for the tip.

Trackside Observations Of A Rail Power Enthusiast

May 13, 2025 by 22 Comments

The life of a Hackaday writer often involves hours spent at a computer searching for all the cool hacks you love, but its perks come in not being tied to an office, and in periodically traveling around our community’s spaces. This suits me perfectly, because as well as having an all-consuming interest in technology, I am a lifelong rail enthusiast. I am rarely without an Interrail pass, and for me Europe’s railways serve as both comfortable mobile office space and a relatively stress free way to cover distance compared to the hell of security theatre at the airport. Along the way I find myself looking at the infrastructure which passes my window, and I have become increasingly fascinated with the power systems behind electric railways. There are so many different voltage and distribution standards as you cross the continent, so just how are they all accommodated? This deserves a closer look.

So Many Different Ways To Power A Train

A British Rail Class 165 "Networker" train at a platform on Marylebone station, London.
Diesel trains like this one are for the dinosaurs.

In Europe where this is being written, the majority of main line railways run on electric power, as do many subsidiary routes. It’s not universal, for example my stomping ground in north Oxfordshire is still served by diesel trains, but in most cases if you take a long train journey it will be powered by electricity. This is a trend reflected in many other countries with large railway networks, except sadly for the United States, which has electrified only a small proportion of its huge network.

Of those many distribution standards there are two main groups when it comes to trackside, those with an overhead wire from which the train takes its power by a pantograph on its roof, or those with a third rail on which the train uses a sliding contact shoe. It’s more usual to see third rails in use on suburban and metro services, but if you take a trip to Southern England you’ll find third rail electric long distance express services. There are even four-rail systems such as the London Underground, where the fourth rail serves as an insulated return conductor to prevent electrolytic corrosion in the cast-iron tunnel linings. Continue reading “Trackside Observations Of A Rail Power Enthusiast” →